In the chapter "Our Love Affair with Personal Pronouns — Especially I, Me, and Mine" of the little book Mindfulness for Beginners, Jon Kabat-Zinn explores nonattachment. He prefaces his comments with:

The Buddha taught for forty-five years. He is said to have said that all of his teachings could be encapsulated in one sentence. If that is so, perhaps we might want to remember what it was, even if we don't necessarily understand it all at first. Imagine forty-five years of profound teaching distilled into one sentence: "Nothing is to be clung to as 'I,' 'me,' or 'mine.'"

Kabat-Zinn goes on to explain:

... What it means is that clinging is optional, that we can recognize it when it arises and choose not to feed it. It means that the selfing habit is a major part of our default setting, that mode of mind that we revert to constantly when we go unconscious or drone on in the automatic pilot doing mode It means that how we related to all our moments, all our experiences, is a choice. It means that we can make the choice, moment by moment, to recognize how much we do cling to "I," "me," and "mine," how self-oriented and self-preoccupied we can be, and then decide not to cling to them, or more reasonably, to catch ourselves when we do. It is saying that we don't have to automatically and with no aware ness fall into the habits of self-identification, self-centeredness, and selfing. What is more, if we are open to looking at ourselves afresh, we can readily see that these thought-habits actually distort reality, create illusions and delusions, and ultimately imprison us.

So when you hear yourself using the words "I," "me," and "mine" a great deal, perhaps it can serve as a signal to quietly reflect on where this is taking you and whether it is serving you well.